DHCP Issue - More info
EDTECH Editor-Eiffert
I did a little testing, and can give more information.
This issue does not pertain to Windows. It is at a much lower layer. The
card will issue a DHCP request, but never receives the acknowledgement.
Booting from a DOS diskette, the card eventually times out trying to
receive an acknowledgement from the DHCP server.
Other machines will work fine on the same switch port. Other machines with
identical cards (3com's 3c905c) will receive IP addresses.
At first I wondered about the DHCP server failing to add new entries when
machines with new MAC addresses entered the network, but booting up a new
PC (Identical to the problematic one) works fine, even on the same port.
Re-booting the DHCP server (Netware 4.11- dhcpsrvr 2.10r), did not help.
(If any of you are Netware junkies maybe you have more info - There are
thousands of leases that have not been issued, and I don't have any
offending errors on the console screen)
I suspect the card to be at fault, as I cannot duplicate the problem on
any other machine, card, port ...
Thanks to all who reply,
Joel VerDuin
District Technology Coordinator
Prairie du Chien Area Schools
"Eduard L. Frerking" <hu...@verio.com>
Win98 will attempt to hold on to the previously assigned IP it
originally received. If it cannot connect to the DHCP server, it
will use the previous, received IP.
Things I would check.
1. Check to see if another machine can receive the an IP from the
DHCP Server.
2. From the faulty local machine, can you ping the DHCP server?
3. Check the DHCP server log to see if the IP which the local
machine has is in the IP scope? What is the status of that IP?
4. Reboot the DHCP server? (Do this after you have turned off
physically all machines that use the DHCP server.) You DHCP Server
might not be giving out IPs even though it thinks it is.
5. I assume that the local machine is setup and configured
correctly.
EDTECH has changed addresses. The new list address is
EDT...@H-NET.MSU.EDU. All subscription commands should be sent to
LIST...@H-NET.MSU.EDU.
EDTECH Editor-Eiffert
To diagnose such problems, I use a packet sniffer. If you have a
copy of Windows NT Server, you have one too. The Network Monitor
Tools and Agent for NT can monitor all packets that are sent to
the NT system including broadcast packets. Since the initial DHCP
protocol is done using broadcasts, you can use NT to peek at the
process. If you want to see everything, you need a better monitor
such as the real Sniffer (http://www.sniffer.com/) or the Network
Monitor from Microsoft System Management Server.
I would take a small hub and place it between the machine in
question and the switch. Put the sniffer on this hub too. Now
you can see what is happening at the packet level.
I have seen machines that can send but not receive packets.
This can be problem with either the card or the cable.
I have also seen problems that look like this when the DHCP
server runs out of available addresses. Other machines can
renew their leases, but the new machine can't get one. Since
you say you have plenty, this isn't the problem.
Walter Horowitz - NoteSys, Inc.
EDTECH Editor-Eiffert
ok, but WHY is the card at fault. I have 3c90x's as well. (10/100).
Joel VerDuin <VERD...@pdc.k12.wi.us>
"Eduard L. Frerking" <hu...@verio.com>
EDTECH has changed addresses. The new list address is
EDTECH Editor-Eiffert
Just a shot here, but have you tried resetting the switch? And/or have you
tried changing the switch port mode, say from half duplex to full, or vice
versa, etc.
> ok, but WHY is the card at fault. I have 3c90x's as well. (10/100).
>
> Joel VerDuin <VERD...@pdc.k12.wi.us>
>
> I did a little testing, and can give more information.
>
> This issue does not pertain to Windows. It is at a much lower layer. The
> card will issue a DHCP request, but never receives the acknowledgement.
>
> Booting from a DOS diskette, the card eventually times out trying to
> receive an acknowledgement from the DHCP server.
>
> Other machines will work fine on the same switch port. Other machines with
> identical cards (3com's 3c905c) will receive IP addresses.
>
> At first I wondered about the DHCP server failing to add new entries when
> machines with new MAC addresses entered the network, but booting up a new
> PC (Identical to the problematic one) works fine, even on the same port.
>
> Re-booting the DHCP server (Netware 4.11- dhcpsrvr 2.10r), did not help.
> (If any of you are Netware junkies maybe you have more info - There are
> thousands of leases that have not been issued, and I don't have any
> offending errors on the console screen)
>
> I suspect the card to be at fault, as I cannot duplicate the problem on
> any other machine, card, port ...
Regards,
-Don
==========================
Don Wolff- Technology Coordinator
Phoenix-Talent School District
Phoenix, OR 97535
mailto:don....@phoenix.k12.or.us
541-535-0200
541-535-7552 (FAX)
EDTECH Editor-Eiffert
Did you try the card in another machine? Sounds like the card is
bad...
Rob Lyons